ß-Pentagalloyl-Glucose Sabotages Pancreatic Cancer Cells and Ameliorates Cachexia in Tumor-Bearing Mice.

Pancreatic cancer cells overexpress the insulin receptor (IR) and the insulin-like growth factor-1 receptor (IGF1R). Activating these receptors, insulin and insulin-like growth factor-1 increase the growth and glycolysis of pancreatic cancer cells. The high glycolysis in pancreatic cancer cells increases whole-body energy expenditure and is therefore involved in the pathogenesis of cancer cachexia. The antagonism of IR and IGF1R may sabotage pancreatic cancer cells and attenuate cancer cachexia. Previous studies have shown that the intracellular regulating system of IR/IGF1R may be functionally interrelated to another intracellular system whose master regulator is hypoxia-inducible factor-1 (HIF-1). In this study, we investigated how the IR/IGF1R and HIF-1 systems are interrelated in pancreatic cancer cells. We also investigated whether a phytochemical, penta-O-galloyl- ß -D-glucose ( ß -PGG), antagonizes IR/IGF1R, sabotages pancreatic cancer cells and alleviates cancer cachexia. We found in MiaPaCa2 pancreatic cancer cells that IR/IGF1R activation increased both the α -subunit of HIF-1 and caveolin-1. This result suggests that IR/IGF1R, HIF-1 α , and caveolin-1 may constitute a feed-forward loop to mediate the effect of IR/IGF1R activation. ß -PGG inhibited IR/IGF1R activity and decreased glycolytic enzymes in MiaPaCa2 and Panc-1 pancreatic cancer cells. When MiaPaCa2 cells were transplanted in athymic mice, their growth was inhibited by ß -PGG or by a HIF-1 α inhibitor, rhein. ß -PGG and rhein also decreased glycolytic enzymes in the tumor grafts and reduced liver gluconeogenesis, skeletal-muscle proteolysis and fat lipolysis in the tumor carriers. Cancer-induced body-weight loss, however, was prevented by ß -PGG but not rhein. In conclusion, ß -PGG combats pancreatic cancer cells and cures cancer cachexia.

The Influence of Curcumin on the Downregulation of MYC, Insulin and IGF-1 Receptors: A possible Mechanism Underlying the Anti-Growth and Anti-Migration in Chemoresistant Colorectal Cancer Cells.

Background and objectives: Mounting evidence shows that curcumin, a bioactive substance originating from turmeric root, has anticancer properties. Additionally, curcumin prevents the migration and metastasis of tumor cells. However, the molecular mechanism involved in the anti-metastatic action of curcumin is not clear. Most studies have suggested that migration inhibition is related to curcumin's anti-inflammatory properties. Curcumin possesses a regulatory effect on insulin and insulin-like growth factor-1 (IGF-1) receptors and signaling. Insulin signaling is one of the important pathways involved in tumor initiation and progression; therefore, we proposed that the anti-metastatic effect of curcumin may mediate the downregulation of insulin and insulin-like growth factor-1 receptors. Materials and Methods: Viable resistant cells resulting from treating SW480 cells with 5-fluorouracil (5-FU) were subjected to curcumin treatment to analyze the proliferation and migration capacity in comparison to the untreated counterparts. To test the proliferation and migration potential, MTT, colony formation, and wound healing assays were performed. Real-time polymerase chain reaction (RT-PCR) was performed to measure the mRNA expression of insulin-like growth factor-1R (IGF-1R), insulin receptor (IR), and avian myelocytomatosis virus oncogene cellular homolog (MYC). Results: Our findings showed that curcumin significantly decreased insulin and IGF-1 receptors in addition to MYC expression. Additionally, the downregulation of the insulin and insulin-like growth factor-1 receptors was correlated to a greater decrease in the proliferation and migration of chemoresistant colorectal cancer cells. Conclusions: These results suggest the possible therapeutic effectiveness of curcumin in adjuvant therapy in metastatic colorectal cancer.

Protective effect of Fisetin against angiotensin II-induced apoptosis by activation of IGF-IR-PI3K-Akt signaling in H9c2 cells and spontaneous hypertension rats.

BACKGROUND: Fisetin, a polyphenolic compound, has drawn notable attention owing to its antioxidant, anti-inflammatory, anti-cancer and neuroprotective effects. However, the cardiac effects of fisetin are not clear yet. HYPOTHESIS: The aim of the present study is to examine the cardioprotective effect of fisetin against Ang-II induced apoptosis in H9c2 cells and in spontaneous hypertensive rats (SHR). METHODS/STUDY DESIGN: The in vitro protective effect of fisetin was evaluated after the cells were treated with fisetin (50 µM/ml/ 24  h) for 2  h prior or after Ang-II administration to induce apoptosis. For in vivo experiments, SHRs were orally administered with fisetin (10  mg/kg) twice a week for 6 weeks. Cellular apoptosis was analyzed by TUNEL staining assay and the modulation in the expression levels of proteins involved in apoptosis and cell survival were determined by western blotting. RESULTS: Our results demonstrate the potent cardioprotective efficacy of fisetin against Ang-II induced apoptosis in H9c2 cells and in SHR models. Fisetin administration reduced the apoptotic nuclei considerably And reduced the expression of apoptotic proteins such as TNF- α, Fas L, FADD, Cleaved caspase-3 and Cleaved PARP and increased the cell survival and anti-apoptotic proteins like Bcl-2, Bcl-xL, p-IGF1R, p-PI3K and p-AKT in both in vitro and in vivo models. CONCLUSION: In conclusion, the results of the present study reveal that fisetin activates the IGF-IR-dependent p-PI3K/p-Akt survival signaling pathway and suppresses the caspase dependent apoptosis.

Curcumol induces cell cycle arrest and apoptosis by inhibiting IGF-1R/PI3K/Akt signaling pathway in human nasopharyngeal carcinoma CNE-2 cells.

Curcumol has been proved to possess antitumor effects in vivo and in vitro in several cancers. Previously, we have found that curcumol induced apoptosis in CNE-2 cells, but its underlying mechanism has not yet been studied well. Recently, our team clarified that curcumol inhibited colorectal cancer cells' growth partially through insulin-like growth factor 1 receptor (IGF-1R) pathway. Given the key importance of IGF-1R pathway in tumorigenesis, we want to explore whether curcumol effects on nasopharyngeal carcinoma (NPC) cells relates to IGF-1R and its downstream pathway inactivation. In this study, we found that curcumol inhibited IGF-1R and p-Akt expression in a dose- and time-dependent way. In addition, it also regulated their downstream GSK-3ß's activity in CNE-2 cells, which further triggering alterations in the expression of cycle- and apoptosis-related molecules, and then leading to G0/G1-phase arrest and apoptosis. Moreover, curcumol's effect on CNE-2 cells was partly eliminated by IGF-1R's agonist IGF-1. In conclusion, our findings indicated that the inhibitory effect of curcumol on proliferation of NPC cells is related to the inhibition of IGF-1R and its downstream PI3K/Akt/GSK-3ß pathway.

Cryptotanshinone inhibits cellular proliferation of human lung cancer cells through downregulation ofIGF-1R/PI3K/Akt signaling pathway.

Lung cancer is one of the most commonly diagnosed malignancies worldwide. Cryptotanshinone (CPT) is a diterpene quinone compound extracted from natural plants and has been reported to have anticancer effects in several cancers including human lung cancer. However, the mechanism by which CPT acts to prevent lung cancer cell growth is largely unknown. In the present study, by using MTT assay, colony formation assay, wound healing and western blotting assays, the effects of CPT on the cell proliferation and migration of human lung cancer cells and the potential cellular signaling mechanisms were investigated. The data demonstrated that CPT exhibited anti-proliferative effects against A549 and H1299 cells. In parallel, the migration of A549 cells was also markedly inhibited by CPT treatment. Further study indicated that CPT not only inhibited the basal phosphorylation level of insulin-like growth factor 1 receptor (IGF-1R) and RAC-alpha serine/threonine-protein kinase (Akt), but also blocked IGF-1 induced IGF-1R and Akt phosphorylation. Finally, it was demonstrated that pretreatment with CPT inhibited IGF-1 induced cell proliferation of A549 and H1299 cells. In conclusion, the results of the present study indicated that CPT inhibits the proliferation and migration of lung cancer cells via a mechanism that involves inhibiting the IGF-1R-mediated phosphoinositide 3-kinase/Akt signaling pathway. The data provides evidence that CPT could be developed as a potential therapeutic agent for the treatment of lung cancer.

GABA tea attenuates cardiac apoptosis in spontaneously hypertensive rats (SHR) by enhancing PI3K/Akt-mediated survival pathway and suppressing Bax/Bak dependent apoptotic pathway.

Cardiomyocyte apoptosis is the major risk factor for the development of heart failure (HF). The purpose of this study was to evaluate the effects of Gamma-aminobutyric acid (GABA) tea on hypertension-induced cardiac apoptotic pathways in spontaneously hypertensive rats (SHR). In order to reveal the mechanisms, 36 male SHR at eight weeks of age, 200 g were divided into six groups. One group was fed water as a control group. Other rats were administered one of the following treatments: GABA tea at dose 150 and 300 mg/kg/day as low GABA tea (LGT) and high GABA tea (HGT) groups, respectively, pure GABA at dose 150 and 300 mg/kg/day as LG and HG groups, respectively, green tea (GT) as control of LGT and HGT groups. After 12 weeks, cardiac tissues were analyzed by histological analysis, western blotting, and TUNEL assays. GABA tea, GT, and pure GABA decreased hypertension-induced cardiac abnormalities, including abnormal myocardial architecture. In addition, GABA tea, GT, and pure GABA dramatically increased anti-apoptotic protein, Bcl2. Furthermore, GABA tea, GT, and pure GABA also decreased activated-caspase 9 and activated-caspase 3. Additionally, the survival associated protein IGF-I and PI3K/Akt were enhanced in cardiac tissues upon treatment. Our results showed an optimistic anti-apoptotic and pro-survival effects of GABA tea treatment against hypertensive rat hearts.

Pharmacophore modeling for identification of anti-IGF-1R drugs and in-vitro validation of fulvestrant as a potential inhibitor.

Insulin-like growth factor 1 receptor (IGF-1R) is an important therapeutic target for breast cancer treatment. The alteration in the IGF-1R associated signaling network due to various genetic and environmental factors leads the system towards metastasis. The pharmacophore modeling and logical approaches have been applied to analyze the behaviour of complex regulatory network involved in breast cancer. A total of 23 inhibitors were selected to generate ligand based pharmacophore using the tool, Molecular Operating Environment (MOE). The best model consisted of three pharmacophore features: aromatic hydrophobic (HyD/Aro), hydrophobic (HyD) and hydrogen bond acceptor (HBA). This model was validated against World drug bank (WDB) database screening to identify 189 hits with the required pharmacophore features and was further screened by using Lipinski positive compounds. Finally, the most effective drug, fulvestrant, was selected. Fulvestrant is a selective estrogen receptor down regulator (SERD). This inhibitor was further studied by using both in-silico and in-vitro approaches that showed the targeted effect of fulvestrant in ER+ MCF-7 cells. Results suggested that fulvestrant has selective cytotoxic effect and a dose dependent response on IRS-1, IGF-1R, PDZK1 and ER-α in MCF-7 cells. PDZK1 can be an important inhibitory target using fulvestrant because it directly regulates IGF-1R.

Dual Inhibition of IGF-1R and ErbB3 Enhances the Activity of Gemcitabine and Nab-Paclitaxel in Preclinical Models of Pancreatic Cancer.

Purpose: Insulin-like growth factor receptor 1 (IGF-1R) is critically involved in pancreatic cancer pathophysiology, promoting cancer cell survival and therapeutic resistance. Assessment of IGF-1R inhibitors in combination with standard-of-care chemotherapy, however, failed to demonstrate significant clinical benefit. The aim of this work is to unravel mechanisms of resistance to IGF-1R inhibition in pancreatic cancer and develop novel strategies to improve the activity of standard-of-care therapies.Experimental Design: Growth factor screening in pancreatic cancer cell lines was performed to identify activators of prosurvival PI3K/AKT signaling. The prevalence of activating growth factors and their receptors was assessed in pancreatic cancer patient samples. Effects of a bispecific IGF-1R and ErbB3 targeting antibody on receptor expression, signaling, cancer cell viability and apoptosis, spheroid growth, and in vivo chemotherapy activity in pancreatic cancer xenograft models were determined.Results: Growth factor screening in pancreatic cancer cells revealed insulin-like growth factor 1 (IGF-1) and heregulin (HRG) as the most potent AKT activators. Both growth factors reduced pancreatic cancer cell sensitivity to gemcitabine or paclitaxel in spheroid growth assays. Istiratumab (MM-141), a novel bispecific antibody that blocks IGF-1R and ErbB3, restored the activity of paclitaxel and gemcitabine in the presence of IGF-1 and HRG in vitro Dual IGF-1R/ErbB3 blocking enhanced chemosensitivity through inhibition of AKT phosphorylation and promotion of IGF-1R and ErbB3 degradation. Addition of istiratumab to gemcitabine and nab-paclitaxel improved chemotherapy activity in vivoConclusions: Our findings suggest a critical role for the HRG/ErbB3 axis and support the clinical exploration of dual IGF-1R/ErbB3 blocking in pancreatic cancer. Clin Cancer Res; 24(12); 2873-85. ©2018 AACR.

Chrysin attenuates testosterone-induced benign prostate hyperplasia in rats.

Benign prostate hyperplasia (BPH) is a common age-related health problem affecting almost 3 out of 4 men in their sixties. Chrysin is a dietary phytoestrogen found naturally in bee propolis and various plant extracts. It possesses antioxidant, anti-inflammatory and anti-proliferative properties. The current study was conducted to explore the role chrysin plays in protection against testosterone-induced BPH in rats. On grounds of a preliminary experiment, a dose of chrysin (50 mg/kg) was chosen for further investigation. Testosterone significantly depleted glutathione, suppressed superoxide dismutase and catalase activities, and elevated lipid peroxidation. Moreover, it markedly scaled down the level of cleaved caspase-3 enzyme, reduced Bax/Bcl-2 ratio and mRNA expression of p53 and p21; conversely, protein expression of proliferating cell nuclear antigen was enhanced. Chrysin alleviated testosterone-induced oxidative stress and restored cleaved caspase-3 level, Bax/Bcl-2 ratio and mRNA expression of p53 and p21 to almost control levels. Chrysin prevented the increase in binding activity of nuclear factor kappa B (NF-κB) p65 subunit, mRNA expression of insulin-like growth factor 1 (IGF-1) and insulin-like growth factor 1 receptor (IGF-1R). These data highlight the protective role of chrysin against experimentally-induced BPH. This is attributed - at least partly - to its antioxidant, antiproliferative and proapoptotic properties.

Oolong tea prevents cardiomyocyte loss against hypoxia by attenuating p-JNK mediated hypertrophy and enhancing P-IGF1R, p-akt, and p-Badser136 activity and by fortifying NRF2 antioxidation system.

Tea, the most widely consumed natural beverage has been associated with reduced mortality risk from cardiovascular disease. Oolong tea is a partially fermented tea containing high levels of catechins, their degree of oxidation varies between 20%-80% causing differences in their active metabolites. In this study we examined the effect of oolong tea extract (OTE) obtained by oxidation at low-temperature for short-time against hypoxic injury and found that oolong tea provides cyto-protective effects by suppressing the JNK mediated hypertrophic effects and by enhancing the innate antioxidant mechanisms in neonatal cardiomyocytes and in H9c2 cells. OTE effectively attenuates 24 h hypoxia-triggered cardiomyocyte loss by suppressing caspase-3-cleavage and apoptosis in a dose-dependent manner. OTE also enhances the IGFIR/p-Akt associated survival-mechanism involving the elevation of p-Badser136 in a dose-dependent manner to aid cellular adaptations against hypoxic challenge. The results show the effects and mechanism of Oolong tea to provide cardio-protective benefits during hypoxic conditions.

Alpinia oxyphylla Miq. fruit extract activates IGFR-PI3K/Akt signaling to induce Schwann cell proliferation and sciatic nerve regeneration.

BACKGROUND: It is known that the medicinal herb Alpinia oxyphylla Miq. is widely used as a remedy for diarrhea as well as the symptoms accompanying hypertension and cerebrovascular disorders. Moreover, it has also been reported that Alpinia oxyphylla Miq. has beneficial effects on anti-senescence and neuro-protection. This study focuses on the molecular mechanisms by which the Alpinia oxyphylla Miq. fruits promote neuron regeneration. METHODS: A piece of silicone rubber was guided across a 15 mm gap in the sciatic nerve of a rat. This nerve gap was then filled with various doses of Alpinia oxyphylla Miq. fruits to assess their regenerative effect on damaged nerves. Further, we investigated the role of Alpinia oxyphylla Miq. fruits in RSC96 Schwann cell proliferation. RESULTS: Our current results showed that treatment with the extract of Alpinia oxyphylla Miq. fruits triggers the phosphorylated insulin-like growth factor-1 receptor- phosphatidylinositol 3-kinase/serine-threonine kinase pathway, and up-regulated the proliferating cell nuclear antigen in a dose-dependent manner. Cell cycle analysis on RSC96 Schwann cells showed that, after exposure to Alpinia oxyphylla Miq. fruit extract, the transition from the first gap phase to the synthesis phase occurs in 12-18 h. The expression of the cell cycle regulatory proteins cyclin D1, cyclin E and cyclin A increased in a dose-dependent manner. Transfection with a small interfering RNA blocked the expression of phosphatidylinositol 3-kinase and induced down-regulation both on the mRNA and protein levels, which resulted in a reduction of the expression of the survival factor B-cell lymphoma 2. CONCLUSION: We provide positive results that demonstrate that Alpinia oxyphylla Miq. fruits facilitate the survival and proliferation of RSC96 cells via insulin-like growth factor-1 signaling.

Zanthoxylum alkylamides ameliorate protein metabolism disorder in STZ-induced diabetic rats.

This study aimed to evaluate the protein metabolism effect of Zanthoxylum alkylamides and to explore the potential mechanism in streptozotocin (STZ)-induced diabetic rats. Diabetic rats were orally treated with 2, 4 and 8 mg per kg bw of alkylamides daily for 28 days. Alkylamides decreased the relative weight of the liver and food intake, significantly increased the relative skeletal muscle weight and significantly decreased the blood urea nitrogen levels. Insulin, insulin-like growth factor 1, total protein (TP) and albumin (ALB), globular proteins and ALB proteins/globulin protein levels in serum significantly increased. TP, RNA content and RNA/DNA ratio significantly increased in the skeletal muscle of diabetic rats. Real-time quantitative polymerase chain reaction results indicated that alkylamides significantly increased the mRNA expression of insulin receptor (InR), IGF1 and insulin-like growth factor 1 receptor (IGF1R) in the liver and skeletal muscle. Moreover, the mRNA and protein expression levels of PI3K, PKB and mTOR significantly increased, whereas those of atrogin-1, muscle ring finger 1 and FOXO in the skeletal muscle significantly decreased. Alkylamides may advance protein synthesis by the PI3K/PKB/mTOR signalling pathway and attenuate the catabolism of protein through the ubiquitin-proteasome pathway. Therefore, it was possible that alkylamides ameliorate protein metabolism disorders in diabetic rats by activating the mTOR pathway.

Combinatorial Drug Screening Identifies Ewing Sarcoma-specific Sensitivities.

Improvements in survival for Ewing sarcoma pediatric and adolescent patients have been modest over the past 20 years. Combinations of anticancer agents endure as an option to overcome resistance to single treatments caused by compensatory pathways. Moreover, combinations are thought to lessen any associated adverse side effects through reduced dosing, which is particularly important in childhood tumors. Using a parallel phenotypic combinatorial screening approach of cells derived from three pediatric tumor types, we identified Ewing sarcoma-specific interactions of a diverse set of targeted agents including approved drugs. We were able to retrieve highly synergistic drug combinations specific for Ewing sarcoma and identified signaling processes important for Ewing sarcoma cell proliferation determined by EWS-FLI1 We generated a molecular target profile of PKC412, a multikinase inhibitor with strong synergistic propensity in Ewing sarcoma, revealing its targets in critical Ewing sarcoma signaling routes. Using a multilevel experimental approach including quantitative phosphoproteomics, we analyzed the molecular rationale behind the disease-specific synergistic effect of simultaneous application of PKC412 and IGF1R inhibitors. The mechanism of the drug synergy between these inhibitors is different from the sum of the mechanisms of the single agents. The combination effectively inhibited pathway crosstalk and averted feedback loop repression, in EWS-FLI1-dependent manner. Mol Cancer Ther; 16(1); 88-101. ©2016 AACR.

Tumour initiating cells and IGF/FGF signalling contribute to sorafenib resistance in hepatocellular carcinoma.

OBJECTIVE: Sorafenib is effective in hepatocellular carcinoma (HCC), but patients ultimately present disease progression. Molecular mechanisms underlying acquired resistance are still unknown. Herein, we characterise the role of tumour-initiating cells (T-ICs) and signalling pathways involved in sorafenib resistance. DESIGN: HCC xenograft mice treated with sorafenib (n=22) were explored for responsiveness (n=5) and acquired resistance (n=17). Mechanism of acquired resistance were assessed by: (1) role of T-ICs by in vitro sphere formation and in vivo tumourigenesis assays using NOD/SCID mice, (2) activation of alternative signalling pathways and (3) efficacy of anti-FGF and anti-IGF drugs in experimental models. Gene expression (microarray, quantitative real-time PCR (qRT-PCR)) and protein analyses (immunohistochemistry, western blot) were conducted. A novel gene signature of sorafenib resistance was generated and tested in two independent cohorts. RESULTS: Sorafenib-acquired resistant tumours showed significant enrichment of T-ICs (164 cells needed to create a tumour) versus sorafenib-sensitive tumours (13 400 cells) and non-treated tumours (1292 cells), p<0.001. Tumours with sorafenib-acquired resistance were enriched with insulin-like growth factor (IGF) and fibroblast growth factor (FGF) signalling cascades (false discovery rate (FDR)<0.05). In vitro, cells derived from sorafenib-acquired resistant tumours and two sorafenib-resistant HCC cell lines were responsive to IGF or FGF inhibition. In vivo, FGF blockade delayed tumour growth and improved survival in sorafenib-resistant tumours. A sorafenib-resistance 175 gene signature was characterised by enrichment of progenitor cell features, aggressive tumorous traits and predicted poor survival in two cohorts (n=442 patients with HCC). CONCLUSIONS: Acquired resistance to sorafenib is driven by T-ICs with enrichment of progenitor markers and activation of IGF and FGF signalling. Inhibition of these pathways would benefit a subset of patients after sorafenib progression.

A combination of Korean mistletoe extract and resistance exercise retarded the decline in muscle mass and strength in the elderly: A randomized controlled trial.

Given the increased concerns about the degenerative decline in the physical performance of the elderly, there is a need for developing effective strategies to suppress the age-related loss of skeletal muscle mass and functional capacity through a lifestyle intervention. This randomized controlled trial examined whether a combination of Korean mistletoe extract (KME) supplement and exercise affected muscle mass, muscle function, and targeted molecular expressions. Sixty-seven subjects aged 55-75years were assigned to placebo, low-dose (1g/d), or high-dose (2g/d) of KME for 12weeks. The body composition was significantly changed in the high-dose group during the intervention period as determined by skeletal muscle mass (P=0.040), fat free mass (P=0.042), soft lean mass (P=0.023), skeletal muscle index (P=0.041), fat-free mass index (P=0.030), percent body fat (P=0.044), and fat mass to lean mass ratio (P=0.030). Knee strength was measured by Cybex, demonstrating a significant effect in the KME groups compared to the placebo group (P=0.026 for peak torque and P=0.057 for set total work), which was more pronounced after adjusting for age, gender, protein, and energy intake (P=0.009 for peak torque and P=0.033 for set total work). The dynamic balance ability was remarkably improved in the high-dose group over a 12-week period as determined by Timed "Up and Go" (P=0.005 for fast walk test and P=0.024 for ordinary walk test). Consistent with these results, RT-PCR, multiplex analyses, and immunocytofluorescence staining revealed that a high-dose KME supplementation was effective for suppressing intracellular pathways related to muscle protein degradation, but stimulating those related to myogenesis. In particular, significant differences were found in atrogin-1 mRNA (P=0.002 at a single administration and P=0.001 at a 12-week administration), myogenin mRNA (P<0.0001 at a single administration and P=0.040 at a 12-week administration), and insulin growth factor 1 receptor phosphorylation (P=0.002 at a 12-week administration). These results suggest that KME supplementation together with resistance exercise may be useful in suppressing the age-related loss of muscle mass and strength in the elderly.

Nuclearly translocated insulin-like growth factor 1 receptor phosphorylates histone H3 at tyrosine 41 and induces SNAI2 expression via Brg1 chromatin remodeling protein.

The insulin-like growth factor-1 receptor (IGF-1R) is a receptor tyrosine kinase that has crucial roles in cell proliferation and protection from apoptosis. It is therefore not surprising that IGF-1R is often found overexpressed in many types of tumors. This has made IGF-1R a prominent target molecule for pharmacological companies to develop new anti-cancer agents. However, several clinical trials during the last 5 years using IGF-1R specific antibodies have shown disappointing results. We have previously shown that upon IGF-1 stimulation, the receptor becomes SUMOylated and translocates into the nucleus of cancer cells to act as a transcription co-factor. Soon after our original study, several others have reported nuclear IGF-1R (nIGF-1R) as well, and some of them have demonstrated a prognostic value of nIGF-1R expression in cancer. In the current study we demonstrate that nIGF-1R binds to and phosphorylates histone H3 at tyrosine 41 (H3Y41) in HeLa cells. Furthermore, our results suggest that phosphorylation of H3Y41 by nIGF-1R, stabilizes the binding of Brg1 chromatin remodeling protein to Histone H3. Our findings suggest that phosphorylated nIGF-1R, rather than total nIGF-1R, plays a superior role in these contexts. We identified SNAI2 oncogene as a target gene for nIGF-1R and its expression was decreased upon mutation of H3Y41 or by Brg1 knockdown. Furthermore, we demonstrate that both IGF-1R and Brg1 binds to the SNAI2 promoter. As SNAI2 protein is implicated in e.g. cancer invasion and metastasis, the nIGF-1R-mediated effects shown in this study may influence such important tumor phenotypic actions.

Emblica officinalis extract downregulates pro-angiogenic molecules via upregulation of cellular and exosomal miR-375 in human ovarian cancer cells.

Ovarian cancer (OC) is highly resistant to current treatment strategies based on a combination of surgery, chemotherapy and radiation therapy. We have recently demonstrated the anti-neoplastic effect of Amla extract (Emblica officinalis, AE) on OC cells in vitro and in vivo. We hypothesized that AE attenuates growth of OC through microRNA (miR)-regulated mechanism(s). The inhibitory effect of AE on proliferation, migration and invasiveness (P≤0.001) of SKOV3 cells and >90% attenuation of tumor growth in a xenograft mouse model suggested multiple targets. RT-qPCR analysis of microRNAs associated with OC showed a >2,000-fold increase in the expression of miR-375 in AE-treated SKOV3 cells that was blocked by an exogenous miR-375 inhibitor (P≤0.001). AE also decreased the gene and protein expression of IGF1R, a target of miR-375 (P≤0.001), and SNAIL1 (P≤0.002), an EMT-associated transcription factor that represses E-cadherin expression (P≤0.003). AE increased E-cadherin expression (P≤0.001). Treatment of SKOV3 cells with AE resulted in increased miR-375 in exosomes in the medium (P≤0.01). Finally, AE significantly decreased the expression of IGF1R and SNAIL1 proteins during attenuation of SKOV3-derived xenograft tumor. Together, these results show that AE modulates cancer cells and the tumor microenvironment via activation of miR-375 and by targeting IGF1R and SNAIL1 in OC cells.

Augmentation of response to nab-paclitaxel by inhibition of insulin-like growth factor (IGF) signaling in preclinical pancreatic cancer models.

Nab-paclitaxel has recently shown greater efficacy in pancreatic ductal adenocarcinoma (PDAC). Insulin like growth factor (IGF) signaling proteins are frequently overexpressed in PDAC and correlate with aggressive tumor phenotype and poor prognosis. We evaluated the improvement in nab-paclitaxel response by addition of BMS-754807, a small molecule inhibitor of IGF-1R/IR signaling, in preclinical PDAC models. In subcutaneous xenografts using AsPC-1 cells, average net tumor growth in different therapy groups was 248.3 mm3 in controls, 42.4 mm3 after nab-paclitaxel (p = 0.002), 93.3 mm3 after BMS-754807 (p = 0.01) and 1.9 mm3 after nab-paclitaxel plus BMS-754807 (p = 0.0002). In subcutaneous xenografts using Panc-1 cells, average net tumor growth in different therapy groups was: 294.3 mm3 in controls, 23.1 mm3 after nab-paclitaxel (p = 0.002), 118.2 mm3 after BMS-754807 (p = 0.02) and -87.4 mm3 (tumor regression) after nab-paclitaxel plus BMS-754807 (p = 0.0001). In peritoneal dissemination model using AsPC-1 cells, median animal survival was increased compared to controls (21 days) after therapy with nab-paclitaxel (40 days, a 90% increase, p = 0.002), BMS-754807 (27 days, a 29% increase, p = 0.01) and nab-paclitaxel plus BMS-754807 (47 days, a 124% increase, p = 0.005), respectively. Decrease in proliferation and increase in apoptosis by nab-paclitaxel and BMS-754807 therapy correlated with their in vivo antitumor activity. In vitro analysis revealed that the addition of IC25 dose of BMS-754807 decreased the nab-paclitaxel IC50 of PDAC cell lines. BMS-754807 therapy decreased phospho-IGF-1R/IR and phospho-AKT expression, and increased cleavage of caspase-3 and PARP-1. These results support the potential of BMS-754807 in combination with nab-paclitaxel as an effective targeting option for pancreatic cancer therapy.

Prolidase-dependent mechanism of (Z)-8,9-epoxyheptadeca-1,11,14-triene-induced inhibition of collagen biosynthesis in cultured human skin fibroblasts.

The effects of polyolefinic compound from roots of Cirsium palustre, (Z)-8,9-epoxyheptadeca-1,11,14-triene (EHT) on collagen biosynthesis, prolidase activity, expression of insulin-like growth factor receptor (IGF-IR), ß1 integrin, MAP kinases (pERK1/2), the transcription factors such as nuclear factor kappa B (NF-κB) and hypoxia-inducible factor-1α (HIF-1α) were evaluated in human dermal fibroblasts treated with micromolar concentrations (40-200 µM) for 24 h. It was found that EHT-dependent inhibition of collagen biosynthesis was accompanied by parallel inhibition in prolidase activity. Since IGF-I is the most potent regulator of both processes and prolidase is regulated by ß1 integrin signalling, the effect of EHT on IGF-IR and ß1 integrin receptor expressions were evaluated. Exposure of the cells to EHT contributed to distinct increase in IGF-IR and slight increase in ß1 integrin receptor expressions. It was accompanied by decrease in expression of pERK1/2, HIF-1α and NF-κB. EHT-dependent inhibition of collagen biosynthesis results from inhibition of prolidase activity, the enzyme involved in collagen biosynthesis.

Targeted therapy for thymic epithelial tumors: a new horizon? Review of the literature and two cases reports.

Surgical resection remains the cornerstone of therapy for early-stage thymic epithelial tumors (TETs), while in advanced or recurrent forms, a multimodality approach incorporating radiation and chemotherapy is required. Given the absence of effective treatment options for metastatic/refractory TETs and the poor related prognosis, there is a compelling need to identify promising 'drugable' molecular targets. Initial reports of activity from targeted agents in TETs derived from anecdotal cases have been often associated with specific activating mutations. Only in recent years, several agents have been formally investigated into prospective clinical trials, with varying success rates. We reviewed the literature on targeted therapy in TETs along with two cases of thymoma achieving striking responses to sorafenib in combination with lapatinib.